亚甲蓝原料药中17种元素杂质含量测定

Assay determination of 17 elemental impurities in methylene blue APIs

目的:依据ICH Q3D最新要求,并综合EP和USP中亚甲蓝质量标准,建立亚甲蓝原料药中铝、镉、铬、铜、铁、铅、锰、汞、钼、镍、锡、锌、砷、钴、钒、锑、锂共17种元素杂质含量的限度和测试方法。方法:样品经微波消解后采用电感耦合等离子体质谱法(ICP-MS)分析,测定模式为碰撞模式,碰撞气为氦气,射频功率1550 W,等离子体气流量15.0 L·min^(-1),载气流量1.05 L·min^(-1),雾化室温度2℃,采集模式为跳峰模式,分析模式为KED模式,定量方式为内标校正的标准曲线法。结果:分析方法验证结果表明,硝酸溶液、试剂空白溶液中各元素的响应值均远小于30%限度溶液,无定量干扰,在考察浓度范围内(25%~200%限度浓度)所有元素线性关系均良好(r均大于0.999),检测限为0.002~1.507μg·g-1,定量限为0.006~4.567μg·g-1,样品加标回收率为82.4%~111.7%,重复性RSD为1.1%~4.1%,中间精密度RSD为1.5%~6.0%,所有验证结果均符合USP<233>和USP<730>的要求。3批样品中的17种元素杂质含量均小于30%限度值,符合ICH Q3D中对于元素杂质控制阈值要求。结论:本方法操作简便、分析速度快、灵敏度高、准确性和精密度良好,可用于亚甲蓝原料药中17种元素杂质的质量控制。

Objective:To establish limits and method for assay determination of 17 elemental impurities(Al、Cd、Cr、Cu、Fe、Pb、Mn、Hg、Mo、Ni、Sn、Zn、As、Co、V、Sb、Li)in methylene blue API in terms of the latest requirement of ICH Q3 D,along with quality specification of methylene blue in EP and USP.Methods:Samples were analyzed by inductively coupled plasma mass spectroscopy(ICP-MS)after microwave digestion.The measuring mode was collision mode with He as the collision gas.The RF power was 1550 W and the plasma gas flow was 15.0 L·min^(-1).The carrier gas was 1.05 L·min^(-1).The temperature of atomizing chamber was 2℃.The acquiring mode was jumping peak mode and the analytical mode was KED mode.The quantitative method was standard curve calibration corrected by internal standard.Results:The results of analytical method validation indicated that response of nitric acid solution and reagent blank solution was far lower than that of 30%limit solution,which demonstrated there was no quantitative interference.All the calibration curves of elemental impurities showed good linearity in the test concentration range(25%-200%limit concentration,r>0.999).Limits of detection(LOD)were 0.002-1.507μg·g-1and limits of quantitation(LOQ)were 0.006-4.567μg·g-1.The spike recoveries were 82.4%-111.7%.The RSD of repeatability and intermediate precision were 1.1%-4.1%and 1.5%-6.0%,respectively.All results of validation were complied with the requirements of USP<233>and USP<730>.The assays of 17 element impurities in 3 batches of samples were all lower than the 30%limit,which satisfied the requirement of control threshold for elemental impurities in ICH Q3D.Conclusion:The established method is simple in operation,rapid in analysis,sensitive,accurate and precise,which is applicable for the quality control of 17 elemental impurities in methylene blue APIs.